In the past, in a case of forming a coil on each tooth section of an annular stator core, in order to prevent a nozzle of a winding machine from interfering with a coil formed on an adjacent tooth, it has been necessary to provide a predetermined gap between adjacent coils, and thus making it impossible to improve the space factor of the coil.
On the other hand, in order to improve the space factor of the coil, a method in which a split core is used is known. Since a coil is formed on each tooth section in a state where a stator core is divided, a concern that an adjacent coil and a nozzle of a winding machine may come into contact with each other is eliminated. As a result, since it is possible to reduce a gap that is provided between adjacent coils, it is possible to improve the space factor of the coil.
However, in a case where a coil is formed on a tooth of each split core, a lead-out line is led out from each coil. As a result, the work of connecting the lead-out line for each phase is required. This work becomes very complicated because insulation between the phases should also be secured while positioning and fixing the lead-out line.
In order to reduce this complexity, for example, there is a technique of reducing handling and connection of a conducting wire by connecting each lead-out line to a plate-shaped bus bar. However, if the bus bar is used, components increase.
Therefore, in a rotary electric machine of Japanese Unexamined Patent Application Publication No. 2000-217293, routing of a coil conducting wire by providing a first groove which is opened radially outward and extends in an axial direction and a second groove which is opened radially outward and extends in a circumferential direction is devised. The coil conducting wire is first led into the first groove from a coil end and subsequently led to a wire connection position on a coil end periphery determined for each phase, in the second groove which is different for each phase. By putting the coil conducting wire in the groove, fixation of the coil conducting wire in the work of treating an end portion becomes easy, and thus workability is improved. Further, since a separate groove is provided for each phase, securement of insulation between the phases becomes easy.
[Patent Document] Japanese Unexamined Patent Application Publication No. 2000-217293
However, in the rotary electric machine of Japanese Unexamined Patent Application Publication No. 2000-217293, the first groove is provided in order to prevent the conducting wires of different phases from crossing each other. However, since a plurality of second grooves is arranged in the axial direction, a concern that the coil conducting wire which is led into the groove on the lower side in the axial direction among the second grooves may cross the coil conducting wire of another phase increases. In order to reduce this concern, in the rotary electric machine of Japanese Unexamined Patent Application Publication No. 2000-217293, a hole penetrating a bottom portion of the first groove is provided.
By passing the coil conducting wire through the hole, a distance in which the coil conducting wire is led into the first groove and then led to the second groove is shortened. For this reason, a concern that the coil conducting wire which is led and the coil conducting wire of another phase may cross each other is reduced. Further, by passing the coil conducting wire through the hole, movement of the coil conducting wire is suppressed from the hole. In this way, a concern that the coil conducting wire may come into contact with another member due to vibration, causing dielectric breakdown, is also reduced.
However, the work of passing the coil conducting wire through the hole is a very difficult process. Further, there is a concern that a leading end of the coil conducting wire may be damaged when passing the coil conducting wire through the hole.